I'm pretty sure everybody in the fandom has written about this moment, but I had a lot of post 4x02 feelings and I just had to write them out.
It seemed to take forever but eventually everyone got settled. Henry left first, headed for Regina's. Then David left with Elsa to get her settled in at Granny's for the night. By the time all that was done Neal woke up ready to eat again. Emma tuned out most of it. She wasn't freezing anymore but she was still a long way from warm and she was so tired. When she thought of her room all the way up the stairs of the loft, she wanted to cry at the effort it would take to get there. As everyone talked and walked around and debated and discussed, she just sat, closing her eyes and turning her face into Killian's shoulder, breathing in the comforting scent of warm leather and soap. His hand stroked her shoulder slowly, never stopping its hypnotic movement.
When Mary Margaret disappeared into her room to feed Neal, Killian dipped his head and murmured in her ear.
"Tired, love?"
"Exhausted," she sighed. "But I'm not ready to face those stairs just yet."
"Right, then," he said, and then he stood abruptly. Emma made a small involuntary noise of protest as his warmth disappeared. "Up you go," he said. And with a huff of breath and a rustle of clothes, she was back in his arms and he was carrying her through the loft to the stairs.
"You don't have to..." She began a half-hearted protest because really, she wanted him to carry her and fuss over her and most importantly, just not let go of her yet.
"Of course I do," he said simply, mounting the stairs without breaking his stride. At the landing, he looked in both directions at the closed doors, because of course he'd never been in her room here or even been upstairs.
"On the left," she murmured.
The door was a little bit ajar so he pushed it open with his foot and continued through the darkness to the edge of her bed. He set her down and turned on the small bedside lamp, casting a soft circle of light that barely reached as far as the foot of the bed.
"Let's get you settled." He crouched to work her boots off. "Your feet are still freezing," he said, hand closing briefly around her toes. She hissed, not even realizing her extremities were still numb until his hand wrapped around her foot. His fingers felt like they were burning her.
"I feel like I'll never be warm again," she groaned.
"Nonsense. You'll be fine by morning." He reached behind her, pulling the quilt up over her shoulders and wrapping it securely around her.
"Killian."
"Yes, love?"
"Will you stay?" His eyes flickered to hers hesitantly. "I just..." She struggled to explain herself as her thoughts kept skittering away. "I don't..."
"No explanation necessary, Swan. Anything you want. Here, let's get another blanket on you." Retrieving the extra quilt folded at the foot of the bed, he wrapped that around her too until she was cocooned in blankets. Standing, he paused for a moment, considering, before shrugging out of his coat and laying it across a chair. He sat on the very edge of her bed and worked himself out of his leather gaiters and boots.
"All sorts of rubbish from the woods on there that you don't want on your bed," he said with a smile, trying to cover the momentary awkwardness. Then he swiveled around and stretched out, partly propped against the headboard. "Come," he said simply, holding his arms open for her.
She went, tipping over and tumbling onto her side, into his embrace. He took a moment to tuck her in, to make sure every inch of her was wrapped up, before he settled back and snugged her body tightly against his. There wasn't anything remotely sexual about it, as she was swathed in multiple blankets and they were both still dressed. For Emma , it was far more intimate than sex. She'd reached out for him because she needed him. And he was there for her, without question or qualification. And she knew he would be.
When Elsa had finally managed to punch a hole in the ice, she hadn't doubted for a second that Killian was on the other side, trying to get to her. And when David had reached in to drag her out, she hadn't felt really saved until Killian's arms were around her, until she'd touched him and reassured them both. She was too tired to puzzle out what it all meant tonight. It didn't matter anyway. He was here. He wasn't going anywhere. That was the revelation she'd just had, which she'd take time to think about and freak out over tomorrow. Or the next day. Some time when he wasn't pressed up against her all warm and comforting and Killian.
Her muscles ached from tensing them so long and her teeth hurt from all the chattering. Killian kept rubbing his hand up and down her back, trying to relax her and soothe her. Finally, with all of him wrapped around her, she started to feel warmer, from the inside out.
"I'm sorry about our date," she mumbled against his collarbone. He chuckled and she felt it all the way through his body and hers.
"You do know how to make an evening memorable, Swan. I'm not sure what we'll come up with for our third date. Might have to march across a frozen tundra or slay a bloody dragon... oh, wait... we've done that one. Perhaps we could scale a cliff face or…."
"Dinner," she whispered, fighting the sleep about to overtake her.
"What's that, love?"
"Next time, we're going to dinner. Just dinner." She couldn't see his face but she could feel his smile, as crazy as that seemed. Like the joy was reaching down and suffusing his whole body.
"Are you asking me out, Swan?"
She chuffed softly, something that was supposed to be a laugh but got lost in quilts and exhaustion.
"You asked first."
"Aye, that I did. And I'll keep asking for as long as it takes."
"Not long," she sighed. "Have to... find Anna and... help Elsa... and..."
"Shhhhh. Yes, the Savior's got some more people to rescue. But they'll wait till morning. For now, sleep."
"Don't leave."
"I won't leave. I promise."
She finally slipped away into sleep, deep and dreamless, as Killian held her and kept vigil. Some time later, when David returned home, he peeked into her room, startling when he found Killian stretched out on her bed, holding her as she slept. They locked eyes over the top of her head. Killian held up his hand and waved David away, a silent gesture that meant "Its okay. I've got this. I'm here for her now." David paused, watching Emma's shoulders slowly rise and fall under the blankets, in the way parents have watched their children sleep since time began, finding reassurance in each indrawn breath. Then he looked at Killian again and smiled before silently closing the door behind him.